The invention relates to an alignment apparatus, with which an instrument to be aligned is mounted on a supporting structure and which comprises a body section to be mounted on the supporting structure, vertically and horizontally alignable alignment sections, of which the first is mounted on the body section and the second is used for mounting the instrument to be aligned, and horizontal and vertical alignment means to align the alignment sections.
The alignment apparatus is used especially in aligning an antenna (and a microwave radio) to a required direction towards another equivalent antenna (and radio) and in keeping the antenna exactly in the set direction, for instance during strong winds. The alignment apparatus is required to enable wireless data transmission, when the wireless data transmission network comprises several radio links with an alignment apparatus and a microwave radio. The alignment apparatus can be used in aligning all antennas, for instance satellite antennas. it can also be adapted to align mirrors and directors.
In such an alignment apparatus, horizontal coarse alignment is implemented when fastening the alignment apparatus to the supporting structure (pole) by mounting it in an approximately correct position. For vertical coarse alignment, the vertical alignment section usually has several initial positions to select from, and the initial setting is then adjusted with vertical fine adjustment.
Apparatus of prior art can be divided into two main groups on the basis of horizontal fine adjustment:
In the first group, the body section to be mounted on the supporting structure (pole) and the alignment sections affecting the horizontal adjustment form an entity which also swivels around the pole when fine adjustment is made. In this case, fine adjustment is greatly dependent on the surface roughness of the pole and the mounting elements and on the friction between the pole and the elements. This means that horizontal fine adjustment becomes unstable and turning the threaded bolt, at times, affects the adjustment and, at times, does not, making the adjustment pulse-like and jerky. Thus, the result is an irregular adjustment, making an exact alignment of an antenna difficult and time-consuming, sometimes even impossible.
In the second group, either the horizontal or vertical alignment section has been arranged to swivel or turn in relation to the body section to be mounted on the supporting structure, for instance so that the vertical alignment section turns vertically in relation to the body while the horizontal alignment section turns in the vertical alignment section. Generally, a disadvantage of such a structure is a small range for horizontal fine adjustment and the fact that to make fine adjustment, it is necessary to open several nuts and bolts before the adjustment and close them after it.
In both above-mentioned groups, several nuts and bolts need to be opened and closed to perform vertical fine adjustment.
As antennas are usually located 20 to 30 meters above land surface in places where wind is strong, installation and alignment conditions are difficult for an antenna installer. In addition to the difficult conditions and the above-mentioned complex adjustment, the installer must move several times from one side of the pole to the other, which requires time and adds to the difficulty and risks of the work.
It is an object of the present invention to produce an alignment apparatus which does not have the above-mentioned problems. This object is achieved by an alignment apparatus of the invention which is characterized in that the alignment means comprise threaded bolts connecting sections turning in relation to each other. The bolts are arranged to turn in both sections in relation to each other so that both ends of the threaded bolts project from the turning sections and both projecting ends are provided with a part enabling the turning of the threaded bolts.
The invention is based on the idea that horizontal and vertical fine adjustment is possible from two opposite sides manually or with a machine, such as a battery drill with a wrench. These characteristics enable a quick fine adjustment. The number of nuts and bolts to be opened and closed is also substantially reduced (approximately 50% as compared to known solutions). At the same time, less tools are required. However, the important thing is that the invention considerably increases the safety of the installer, because he does not need to move around so much.
An advantage of the invention is also that if the antenna must be installed on the other side of the pole, the adjustments can still be made without disassembling parts of the alignment apparatus, because the alignment apparatus is xe2x80x98symmetricalxe2x80x99 due to the fact that adjustment can be made on two sides. The alignment apparatus can also be made compact, which enables its installation close to the pole.